Designed to mount on a gas block with a Mil-Std-1913 rail. These flip front sights can be mounted on the gas block of your AR-15, M16, or M4.  When mounted these will fold forward to lay flat and out of the way of the field of view of your optics.

For the sights to align correctly with a rear Mil-Spec height rear sight, the top of the Mil-Std-1913 rails on the gas block must measure .925" over the center of the bore. Please contact the manufacturer of your gas block to insure it meets this measurement before ordering this product.

(Gas block is not included.)